Technical terms can be confusing. Here’s a breakdown of screen sharing, screen mirroring, and screencasting
The difference between wireless screen sharing, screen mirroring and screencasting
Our devices are able to increasingly interact with each other in ways that are bringing us closer and closer to eliminating cables for good. There are solutions that allow us to wirelessly exhibit the contents of a computer, tablet, or mobile device to a larger display, such as a TV.
That said, it’s important to know that wireless interactions work differently, depending on what content you want to be shown and how you prefer to go about it. In this article, I’ll break down the basics of screen mirroring, screencasting (also known as media streaming) and screen sharing (also known as desktop sharing).
First of all, what does “streaming” really mean?
Maybe you’ve heard someone say that they streamed a movie, a podcast, or a slideshow. What streaming refers to is a continuous flow of information (in the form of visual and/or audio data). In other words, streaming means delivering data “live” – whatever sort of content you have on your device’s screen. It can be conscious, as with presenting in a meeting, or more passively presented, in the form of digital signage. With that in mind, take note that the three terms that follow—mirroring, casting, and sharing—are each a different way of streaming.
Screen mirroring
As the name suggests, screen mirroring allows you to project, or “mirror”, what is on your smartphone, tablet or computer and show it on your TV screen, projector, or external monitor without needing to use a cable. The TV or projector will present an exact replica of what’s going on on your computer or mobile device, including any movement (e.g., editing a text document or playing/pausing a video).
Unlike when we look into a glass mirror, screen mirroring won’t horizontally flip what you see. So when you hear mirroring, think copying. This is great for viewing local content such as pictures, videos, documents, and professional or educational presentations. During a presentation, you can even choose to only present a slideshow, while still getting to look at your personal notes—known as presenter mode.
Screen mirroring requires software running on the device you want to send content from, and a receiver on the display that you’re sending it to.
Examples of screen mirroring are what you can do with AirPlay, which is Apple’s “protocol” that allows you to mirror the contents of your Mac, iPhone or iPad to a screen connected to an Apple TV.
While AirPlay will mirror your screen, it’s also smart enough to sometimes switch to a casting mode, so that you can fiddle with the controls on your iPhone while watching a video (without having these movements copied).
Miracast is the Microsoft equivalent, which lets Android smartphones and Windows tablets and computers to mirror to Miracast-compliant receivers.
You can find more on screen mirroring here.
Screencasting
The major difference between screen mirroring and screencasting is the way in which the content is shared to a display. In the case of screencasting, your TV wirelessly receives online content via a digital media player to a TV via a wireless connection.
Screencasting uses an app to send movies, video clips, and music from your phone, tablet or computer to your TV screen. For example, you can use the YouTube of Netflix app on your phone to cast video over the internet from the YouTube or Netflix servers to your TV display.
With casting, you can use your phone or tablet while casting a movie without any interruption. When casting you’re not streaming video from your mobile device to the TV display, but rather using your mobile to initially set up the cast, and then letting the YouTube or Netflix server do the rest of the work.
The term casting is synonymous with products like Chromecast which it has largely stemmed from. You could use your phone to start a movie on your friend’s Chromecast-equipped TV at their house, and then leave. The movie would still continue to play.
Screen sharing
Screen sharing is also known as desktop sharing. While mirroring and casting are done with a smaller device (e.g., mobile or laptop) and a larger display (e.g. TV or projector), screen sharing generally involves making a copy of your computer screen to other computer screens.
This is especially useful when you want to go through a slideshow or document with someone who is in a different location, such as when offering remote training sessions online.
There is a multitude of screen sharing solutions, such as those provided by GoToMeeting, Slack, Skype, etc. Screen sharing is very useful for peer-to-peer collaboration (e.g., working on a design mock-up), but it’s not usually used for professional or educational presentations.
Presentations rather call for individuals to direct their attention to a person who is physically present and using one (or two) displays to show visual aids that are complementary to the message of the speaker.
Sharing involves all participants looking at their screen, to follow along with the person who is communicating from a remote location. It takes place when a host computer (the person sharing) sends information to a remote computer (or multiple depending on the number of participants) over the network. This information is encrypted, meaning that it’s converted into a code for security reasons.
The software used for sharing only sends updates on the sections of the screen that have changed. By only sending what’s necessary, bandwidth (the capacity of a wired or wireless network) usage is reduced.
“… and then there’s Airtame”
What can you do with a wireless product like Airtame? Let’s break it down based on what’s been outlined so far:
Airtame and screen mirroring
Airtame enables you to mirror your screen to one (or multiple) displays at the same time (provided that each has the Airtame device attached). This is an inclusive solution, as you can run the Airtame app on Windows, MacOS, Linux, Chromebook, Android and iOS devices. All it takes is clicking a button in the app, and the Airtame-equipped screen (TV, projector, or monitor) will show an exact copy.
We recently released our beta-version Single Window Sharing feature, allowing participants to share a specific window (e.g., document or slideshow), while simultaneously being able to look at different content on their computer screen.
Screen mirroring with Airtame is a great solution for classrooms and meeting rooms. Rather than using a casting device that’s designed for home entertainment, screen mirroring lets participants engage in a meeting or discussion while easily controlling what they show on a large display. Once you cut away the cables the possibilities are really endless.
Airtame and screencasting:
Airtame does not work with casting. So if you’re looking for something that lets you stream media such as Netflix, then a home entertainment product would be a better choice.
Airtame and screen sharing:
Airtame itself is not a screen sharing solution. You cannot use the Airtame app or device to show content among computers (which is the purpose of screen sharing).
That said, you could potentially use Airtame together with a screen sharing solution. For example, someone working remotely can share their screen with an on-site computer (e.g., using GoToMeeting).
The on-site computer, running the Airtame app, can then be mirrored to a large TV with the Airtame device plugged in. This can fit a classroom context if a remote instructor would rather have people pay attention to a single display at the front of a room, rather than to their individual laptops.
Summing up
| Screen Mirroring | Screencasting (media streaming) | Screen Sharing (desktop sharing) | |
|---|---|---|---|
| What it does | Copies a device’s screen, so that the same thing is visible on another screen(s) | Allows you to play content from one device onto the other | Copies a primary screen, allowing the remote viewer(s) to see everything that the first user sees, including what the “sharer” is doing |
| Screen view | Two screens show the same thing | Two screens showing something different | Two or more screens can show the same thing |
| Content | Everything on the screen is shown | Only specific content plays | Everything on the screen is shown |
| Internet | Not necessarily needed as a connection can be made using built-in WiFi (e.g., the receiver’s own access point) | Often used with home WiFi, although can sometimes be made using built-in WiFi (e.g., the receiver’s own access point) | Usually needed |
| Multitasking | Whatever is happening on the primary device is shown on the second screen (unless using presenter mode) | The primary device can be used to do something else while casting | Whatever is showing on the shared screen is visible to the other one(s), and viewers can also be allowed to make changes |
| Screen timeouts | If the screen of the primary device is blacked out, the secondary device also blacks out | The screen of the primary device can be blacked out | If the screen of the primary device is blacked out, the other screens also show a black screen |
| Apps | Nearly everything can be viewed via screen mirroring | Not all apps support casting | Nearly everything can be viewed via screen sharing |
| Local content | Supports local content such as photos, documents, and videos | Usually does not support local content | Supports local content |
Many terms related to wireless streaming emerged around the same time, with no united industry standard for what means what. Clarification is needed so that people don’t continue to get things mixed up. Whenever a colleague is in doubt, feel free to point them here.
